1. Field of the Invention
The present invention relates to a method of driving a liquid crystal matrix panel which has by itself a memory property, such as a ferrodielectric liquid crystal panel, and is usable in a display device.
2. Description of the Prior Art
Recently in the field of information processing apparatus represented by computers and in the field of video equipment represented by television and video tape recorders, there is a growing demand for a thin-type display device of large display capacity.
As an example of conventional driving method of liquid crystal matrix panel, the driving method of ferrodielectric liquid crystal is described below.
Conventional high speed driving methods of bistable ferrodielectric liquid crystal matrix panel are 1) the method applying a high voltage capable of setting the liquid crystal in a desired state regardless of the display data before the selection period (e.g. see the Technical Research Report of Japan Society of Electronic Information and Communications, Vol. 87, No. 68), 2) the method of inverting the polarity sequence of the applied voltage at scanning period intervals while selecting two scanning electrodes simultaneously (e.g. see Japanese Laid-open Patent 63-151929), and 3) the method of applying a voltage having a duration capable of setting the liquid crystal in a desired state regardless of the display data before the selection period (e.g., see Japanese Laid-open Patent 62-56937).
However, in the driving method of 1), the driving voltage becomes high, so that it is difficult to integrate the drive circuit on a semiconductor chip. In the driving method of 2), the operation margin varies with the display pattern. In the driving method of 3), three different voltages must be applied to the scanning electrodes at the same time, and therefore a driver having a simple structure cannot be used.